Aluminum alloy



1951 I H. BURKHARDT ,5

ALUMINUM ALLOY Filed Sept. 9, 1949 1N VENTOR Hans Bun/mrdf BY w fizg /wfw ATTORNEYS i atentecl lqov. 6,

ALUMINUM ALLOY Hans Burkhardt, OberurseI-on-Taunus, near Frankfurt-on-the-Main, Germany, assignor to Vereinigte Deutsche Metallwerke Aktiengesellschaft,

Frankfurt-on-the-Main,

Ger-

many, a corporation of Germany Application September 9, 1949, Serial No. 114,883

In Germany October 1, 1948 4 Claims.

This invention relates to an aluminum alloy and has for its object to provide an alloy of generally improved properties.

A special object of the invention is to provide an aluminum alloy which has very favorable sliding or anti-frictional properties, more particularly at elevated temperatures, and is suitable for the manufacture of shaped articles, such as pistons, bearing bushes, engine cylinders, packing rings, or other machine parts.

Another object of the invention is to provide an alloy of improved mechanical properties, more particularly as regards its mechanical strength, combined with favorable sliding or anti-frictional properties.

Another object of the invention is to provide an aluminum alloy whose hardness and mechanical strength can be controlled by various additional components.

I have found that an aluminum alloy which has particularly favorable properties can be obtained by the composition of about 0.5 to 3% of calcium, 0.5 to 3% of iron, the balance consisting substantially of aluminum, all by weight. In

addition to said components, a certain percentage of other metals may be contained in the alloy without a detrimental effect upon the properties of the alloy. It is also possible to use a certain percentage of an impure scrap metal for smelting the alloy. Among the additions that may be contained in the alloy are silicon, up to about 1.5 percent, zinc up to about 2 percent, copper, manganese, lead and magnesium, each up to about 1 percent, all by weight. Depending on the proportions of these additions, they bring about a more or less intensive hardening of the alloy or improved anti-frictional qualities. 'Thus, the hardness of the alloy can be adapted to the purpose for which the alloy is intended to be used. The mechanical properties, e. g., the strength of the alloy can also be improved by these additions.

A preferred alloy for the production of slide bearings was found to be as follows:

1.5% by weight of calcium 2% of iron remainder aluminum Moreover, good results have been obtained by adding 0.5 to 1.2 percent of silicon to the said components.

My novel alloy can be used for east as well as wrought alloys for the manufacture of machine parts exposed to frictional stresses. The alloys can be easily subjected to any non-cutting shaping, such as pressing, drawing, or rolling operations. Hence, the alloys can be worked up into shaped articles in the form of castings or pressed extrusion-moulded or die-cast parts or in the form of drawn tubes or metal sheets which are then worked up into alloys. Since my novel alloy lends itself for rolling operations and in general can easily be deformed, it can be used especially for the production of rolled bushings.

In regard to its anti-friction or hearing properties the alloy according to the present invention is very similar to lead bronze and, therefore, it can be used to replace lead bronzes in many instances. Similar to lead bronze the aluminum alloys according to the present invention can also be joined with steel or any other hard metal or metal alloy or with certain aluminum alloys of a higher strength by a plating or welding operation, for producing bearing linings or bushes or other articles of a bimetal structure.

An embodiment of a shaped article which may be made of my novel alloy is exemplified in the drawing, in which:

Fig. 1 is an axial section, and

Fig. 2 is an end view of the said embodiment.

In the drawing, the outer shell I of the shaped article which may be used especially as a bearing bushing, cylinder lining, piston, slide bushing or the like, may consist of an aluminum or other alloy of a high mechanical strength while the inner part 2 may consist of an alloy according to the present invention. It will be understood, however, that it is also contemplated, within the purview of the present invention, to make the inner part of an aluminum or other metal alloy of a high mechanical strength while the outer part consists of my novel alloy, depending on the use for which the shaped body is actually intended.

Shaped bodies of the type as shown in the drawing may be produced, for instance, by superposing a sheet of an alloy according to the present invention and a sheet of a harder metallic material and plating said superposed sheets in the manner known per se. The bimetal sheet thus obtaind may then be rolled into the shape of a sleeve or bushing as shown. It is also possible to superpose three sheets, e. g. in such a way that a sheet of a harder metallic material is sandwiched between two sheets of an antifrictional alloy according to the present invention and plated therewith, so as to obtain a body which has two surfaces of good sliding properties combined with a relatively high mechanical strength produced by the inner carrier metal.

While the invention has been described in detail with respect to certain now preferred examples and embodiments of the invention it will be understood by those skilled in the art after understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention and it is intended, therefore, to cover all such changes and modifications in the appended claims.

Having thus described my invention, I claim:

1. An alloy consisting of 0.5 to 3% of calcium, 0.5 to 3% of iron, and the remainder aluminum.

2. An alloy consisting of 1.5% of calcium, 2% of iron, and the remainder aluminum.

3. An alloy consisting of 0.5 to 3% of calcium, 0.5 to 3% of iron, 0.5 to 1.2% of silicon, and the remainder aluminum.

4. An alloy consisting of 1.5% of calcium, 2% of iron, 0.5 to 1.2% of silicon, and the remainder aluminum.

HANS BURKHARDT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,412,280 Frary Apr. 11, 1922 2,277,023 Steiner et a1. Mar. 17, 1942 FOREIGN PATENTS Number Country Date 295,265 Great Britain Aug. 27, 1928 830,798 France Aug. 9, 1938 OTHER REFERENCES Mechanical Properties of Metals and Alloys,"

Circular #0447, published by the Bureau of Standards, 1943, page 22. 

1. AN ALLOY CONSISTING OF 0.5 TO 3% OF CALCIUM, 0.5 TO 3% OF IRON, AND THE REMAINDER ALUMINUM. 